A new study from the University of Minnesota and Iowa State University fingers Monsanto’s genetically modified corn and soybean crops as the culprit behind monarch butterflies’ declining populations.
Between 1999 and 2010, the same period in which so-called GMO crops became the norm for farmers, the number of monarch eggs declined by an estimated 81 percent across the Midwest, the researchers say.
About 94 percent of U.S. soybean farmers and 72 percent of corn farmers use Monsanto’s Roundup Ready crops. All that genetically altered ag kills butterflies, researchers say, by decimating their prime breeding zones: milkweed plants on farms. Roundup Ready corn and soy are designed to be resistant to the herbicide Roundup. Because their crops are immune, farmers spray Roundup indiscriminately to kill off weeds — including milkweed — and monarch butterflies wind up paying the ultimate price.